1. Field of the Invention
This invention relates in general to an adjustable mounting device for use with a post mounted item such as a chair. More specifically, the invention enables the operator to swivel the item 360-degrees in a rotational direction and to slide it backward and forward on rollers in a horizontal direction, by adjusting a single telescoping handle that may be retracted when it is not in use.
2. Description of the Related Art
Because of the high speeds and heavy shaking involved with vehicles such as pleasure boats, chairs for these vehicles are typically mounted on a support post fixed to the underlying deck. To permit the occupant to adjust the rotational and longitudinal position of the chair, a sliding and swiveling device is mounted between the chair and the stationary post. The cam locking type sliding and swiveling device, as described in U.S. Pat. No. 5,704,729, the disclosure of which is incorporated herein by reference, includes a slide plate and a holder. The holder has a lower cylindrical sleeve portion and an upper web portion. The sleeve is shaped to receive the post and it is rotatably coupled to the post in a manner that allows the holder to swivel 360-degrees in a rotational direction around the post. The top of the upper web portion terminates in a pair of parallel longitudinal skids. The slide plate has an upper surface and a lower surface. The upper surface supports an item such as a chair. The lower surface of the slide plate has a pair of parallel longitudinal tracks which receive the skids of the holder, and in this manner the slide plate is slidably coupled to the holder permitting the slide plate to slide longitudinally with respect to the holder. The device also features a first locking assembly for releasably locking the slide plate and holder against rotation with respect to the chair post. A second locking assembly is provided for releasably locking the slide plate and holder against longitudinal sliding. The device features a handle and an assembly for triggering a release of the first locking assembly upon rotation of the handle in a first direction (e.g., clockwise) and for triggering a release of the second locking assembly upon rotation of the same handle in a second direction (e.g., counter-clockwise). Biasing devices are provided to place the two locks or locking assemblies in a locking state when the handle is not rotated in one direction or the other.
The slide plate slides on a pair of parallel tracks. An item such as a chair is attached to the upper surface of the slide plate. When the overlying chair is stationary, static friction forces develop between the track and the skid. Thus, to move the chair forward or backward, the operator must shove the chair with enough force to overcome the static friction forces, and this can cause the chair to slide past or overshoot the desired position. To slide the chair back from the over-shot location to the desired position, sufficient force must be developed once again, and this may cause the chair again to slide past the desired location.
When an item such as a chair is mounted to a boat deck utilizing a conventional sliding and swiveling device, the chair obstructs precious deck space, whether or not it is in use. In addition, the handle must protrude laterally outward from the device to an outer edge of the chair so that the operator can reach it with ease. Thus, the handle of the sliding and swiveling device as well obstructs the boat deck space.
It can be understood from the above discussion that the prior sliding and swiveling device offers serviceable performance. However, longitudinal adjustment of the prior arrangement is inaccurate and inconvenient, because the operator must shove the chair hard enough to develop a large momentum to overcome static friction forces, and as a result the desired new location may be over-shot. Furthermore, the device and the item that the device supports obstruct space, whether or not they are in use. Finally, the rotational locking mechanism, or thrust plate, is composed from numerous components, and as a result it is relatively complicated to manufacture.
It is therefore an object of the invention to provide a sliding and swiveling device that develops a minimal amount of static friction when it is at rest, requires less force for horizontal movement, and does not obstruct lateral space when the device is not in use. A still further object is to provide such a device that utilizes a rotational locking mechanism having a minimal number of components.